#include<fstream.h>
#include<math.h>
long long n,p,i,cn,ci;
int main()
{int c=1;
ifstream in("frac.in");
ofstream out("frac.out");
in>>n;
in>>p;
if (n%2==0)
	{for (i=3;i<=pow(2,63)&&c!=p;i=i+2)
		{cn=n;
		ci=i;
		while (ci!=cn)
			{if (ci>cn)
				ci=ci-cn;
			else
				cn=cn-ci;
			}
		if (ci==1)
			c++;
		}
	i=i-2;
	}
if (n%2!=0)
	{for (i=2;i<=pow(2,63)&&c!=p;i=i+2)
		{cn=n;
		ci=i;
		while (ci!=cn)
			{if (ci>cn)
				ci=ci-cn;
			else
				cn=cn-ci;}
		if (ci==1)
			c++;
		}
	i=i-1;
	}
out<<i;

in.close();
out.close();
return 0;
}